A Sino-Indian war would be very, very different from the Russo-Ukrainian war.
The poor showing of the VKS has intrigued every observer, especially western ones who are accustomed to airpower being of critical importance to shape the operations on the ground. But the very dysfunctional setup of the Russian armed forces, where despite all reforms aimed at promoting joint operations, the air force is still doing its own thing instead of supporting the ground forces, should not be expected from the People's Liberation Army, which is organized differently.
Furthermore, both Russia and Ukraine are heirs of the Soviet Union doctrine which knew of its airpower inferiority compared to NATO and therefore aimed at air interdiction instead of air penetration. So in Ukraine we have two weak air forces and two relatively strong air defense forces. But on the other hand, the Russians have railroads allowing fast and easy transport by land to their occupied territories. So we have a scenario where airpower is crippled, and land power gets a supply boost.
While it's true, the issue is neither side can mass enough air power against each other to make an impact on the ground forces of either side. The IAF lacks mass today while PLAAF lacks terrain. PLAAF cannot operate at the tempo required to assist ground forces. So both sides are likely to employ their assets for strategic effect ranging from interdiction to deep strike, while restricting CAS to helicopters and a few squadrons of jets. IA officers regularly complain about lack of dedicated fixed-wing aircraft for CAS.
Add to that, the existence of a very complex and fast-growing ADGE on both sides further complicates CAS and search and destroy missions. A lot of assets will be necessary to penetrate enemy lines during offensives as well.
We have to see what the situation is like a decade down the line, say, for example, the Chinese attack helicopters become more usable in the mountains while India actually gets a lot of attack helicopters, alongside modern Western jets and more precision weapons.
Now if we transport this to a war between China and India, the first, massive, difference is that between the two countries, instead of having a mostly flat plain full of roads and railroads that connect both countries, and where the worst challenge to mobility is that it's excessively muddy in Autumn and Spring, there's a giant mountain range that's the highest on the entire planet. I wouldn't expect howitzers to roll across the border as easily through the Himalaya as they did in Ukraine. On the other hand, the mountains provide excellent terrain masking allowing aircraft to advance undetected and just pop up quickly to throw a volley of cruise missiles before disappearing behind cover again.
Terrain advantage belongs to the artillery though, compared to aircraft.
Low ceilings, fog, and storms common to mountain regions may degrade air support operations. Although, global positioning system (GPS) capable aircraft and air delivered weapons can negate many of the previous limitations caused by weather. Terrain canalizes low altitude air avenues of approach, limiting ingress and egress routes and available attack options, and increasing aircraft vulnerability to enemy air defense systems. Potential targets can hide in the crevices of cliffs and the niches of mountain slopes, and on gorge floors. Hence, pilots may be able to detect the enemy only at short distances, requiring them to swing around for a second run on the target and giving the enemy more time to disperse and seek better cover. Additionally, accuracy may be degraded due to the need for pilots to divert more of their attention to flying while simultaneously executing their attack.
Helicopters negate some of the disadvantages, like the Longbow + Hellfire combo, but one hopes air defences can handle them.
There are other problems too, as listed in this article.
www.ipcs.org
Although it's from 1999, tech has changed quite a lot, but not all problems have been surmounted, like the need for very accurate intelligence or questionable survivability during search and destroy missions.
In India's context, most of our artillery is concentrated along the border, but the Chinese have to come from half a continent away. And we have ridiculous amounts of mountain fighting experience, over 3 decades, courtesy of our friendly western neighbour. We will also have access to Western intelligence, which I hope gets into the right hands quickly enough.
